Where is that particular "C:" drive actually located? If it's not on the server, you'll need to us a "share" with a machine name and share name as the first two elements in the path of both the source and the target.
IIRC, you'll need to at least specify a file pattern as a part of the source. "*" for all files, for example.
Of course, if you're just trying to rename a directory, then what you have will do it, provided the "C:" drive is on the server. And, of course, if you ARE loading files onto your server, especially the "C:" drive, then you're committing a very worst practice as best and doing something that could cost you your job if you accidentally rename an OS directory.
Here's the command structure for MOVE, just as a reminder.
Moves files and renames files and directories.
To move one or more files:
MOVE [/Y | /-Y] [drive:][path]filename1[,...] destination
To rename a directory:
MOVE [/Y | /-Y] [drive:][path]dirname1 dirname2
[drive:][path]filename1 Specifies the location and name of the file
or files you want to move.
destination Specifies the new location of the file. Destination
can consist of a drive letter and colon, a
directory name, or a combination. If you are moving
only one file, you can also include a filename if
you want to rename the file when you move it.
[drive:][path]dirname1 Specifies the directory you want to rename.
dirname2 Specifies the new name of the directory.
/Y Suppresses prompting to confirm you want to
overwrite an existing destination file.
/-Y Causes prompting to confirm you want to overwrite
an existing destination file.
The switch /Y may be present in the COPYCMD environment variable.
This may be overridden with /-Y on the command line. Default is
to prompt on overwrites unless MOVE command is being executed from
within a batch script.